Privacy Preserving Data Mining (PPDM) enables one or several parties to conduct the normal data mining operations without knowing the data (or without knowing some part of the data). PPDM recently has received more and more attention because of the increasingly important privacy concerns. In general, there are two approaches for PPDM problems. One is the randomization approach, in which, data are randomized before being disclosed to the data miner. The second approach is the secure multi-party computation approach, in which, data are disguised using cryptographic methods to allow multiple parties to conduct a joint computation without disclosing one party's private data to the others. In this talk, I will give an overview of the PPDM problems and both approaches. I will present some of my past and current work in this area. Considering that some students might not have background in data mining, I will present the work in a way that requires no background in data mining.